Why is my plumbing backing up, even after being roto rooted a few days ago?

About a week ago we had our toilet and bath tub back up, after my daughter took a shower it would not drain from either. We called roto rooter, and about 207$ later we were back in business. Now my husband just got out of the shower and its blocked up again! We are not on a septic system, in a single story ranch for the early 70s in the south east. Any ideas as to what it could be? Thanks again!